Field of the Invention and Description of the Prior Art
This invention relates to an improved drive belt or track assembly particularly useful for snowmobiles and it particularly relates to an improvement in a unitarily formed drive belt assembly having rigid guide clips for guiding the movement of the drive belt relative to a slide rail type of suspension system commonly used with snowmobiles.
Continuous or endless drive belts or tracks are used in connection with snowmobiles for engaging the ground, snow or ice in order to propel the snowmobile forwardly. Generally speaking, the drive belt or track for a snowmobile has a width substantially equal to the seat portion and is drivably suspended on the frame of the snowmobile. A drive track is generally positioned on the rear portion of the snowmobile and a pair of steerable skis support the front end of the snowmobile. One type of snowmobile drive belt design is shown, for example, in the Kell U.S. Pat. No. 3,623,780. Such drive belts are made in three continuous sections including a central section, and two spaced side sections. The sections are interconnected to metal cleats which also act as drive cleats which provide positive traction with the ground for propelling the snowmobile in a forward direction in response to movement of the drive belt.
Another type of drive belt assembly, particularly useful for snowmobiles, is shown in Maki U.S. Pat. No. 3,930,689 wherein partial or two-thirds cleats are used in cooperative relationship with flexible lugs or projections on the outer surface of the drive belt in order to provide not only positive forward traction but to also substantially avoid side slippage of the rear of the snowmobile.
One reason why snowmobile drive belts are constructed with three spaced endless sections is that the bottom surface of both slide rails of a suspension system are positioned in the spaces between the central drive belt section and each of the outer drive belt sections and the bottom surfaces of the slide rail bear against the inner surface of each of the cleats. Generally, the slide rail is constructed of a rigid plastic material, such as molded nylon, while the cleats are constructed of a metal to thereby provide for low frictional resistance between the slide rail and the surfaces of the cleats.
Still another type of track or drive belt assembly for snowmobiles is unitarily formed, that is, the central track section is interconnected to a pair of side track sections by substantially unitary interconnecting portions, which are preferably reinforced, as with a reinforcing rod, for example, so as to securely mount the two side track sections to the central section. In such a unitarily formed drive belt or track assembly, metal drive cleats are not used and it is, therefore, additionally necessary to secure a plurality of track guide clips to the unitary members that interconnect the central drive belt section to the side belt sections. In the prior art, such track guide clips have generally comprised a metallic member that is secured rigidly to the interconnecting members and that an offset portion of the clip is located on the outside of the central drive belt section so as to form lateral guides adjacent the outer sides of the slide rails so as to substantially avoid the slide rails from becoming disengaged from the drive belt. With the prior art track guide clips, however, they unduly frequently became broken, resulting in a relatively high incidence of maintenance in order to replace the broken clips.